In semiconductor manufacture, large scale electronic devices are designed, and then the design is checked to insure that the devices will function properly. This check usually consists of a computer based analysis to determine if the design conforms to manufacturing parameters. Several different design checks include design rule checking (DRC) and optical proximity correction (OPC).
DRC determines whether a particular design layout satisfies a series of recommended parameters called design rules. Typically, the design rules are a series of parameters governed by semiconductor manufacturing that enable a designer to verify the correctness of a layout and/or photomask set. For example, design rules may specify certain geometric and connectivity restrictions to ensure sufficient margins to account for variability in semiconductor manufacturing processes. The design rule check ensures that most of the parts work correctly. As manufacturing increases in complexity, design rules have become increasingly more complex with each subsequent generation of semiconductor design.
DRC usually takes, as input, a layout in the GDSII standard format. GDSII format represents the design layout in a binary format for representation of planar geometric shapes, text labels, and some other information in hierarchical form. The DRC produces a report of design rule violations to allow a finalized design to be produced.
OPC is a photolithography enhancement technique commonly used to compensate for image errors due to diffraction or process effects of photolithography. For example, OPC may discover and correct such effects as differences between features in regions of different density (e.g., center vs. edge of an array, or nested vs. isolated lines), and line end shortening (e.g., gate overlap on field oxide).
DRC and OPC are computationally intense tasks. If run on a single CPU, designers may have to wait up to a week to get the result of a DRC or OPC for modern high; density designs. Accordingly, methods and systems are needed to speed up design checking processes.